Monetary Accommodation of Supply Shocks under Rational Expectations

In dealing with the expectationists' arguments, I will divide them (somewhat artificially) into two groups. Arguments in the first group, which I call "present disaster" arguments, allege that econometric models err by understating the reaction of inflationary expectations. For example, it is claimed that a policy of monetary accommodation would increase inflationary expectations, shift the short-run Phillips curve upward, and defeat the purpose of the expansionary policy. Arguments in the second group, which I call "future disaster" arguments, are more subtle, but also more elusive. The idea is that by informing private agents that it will accommodate supply shocks in the future, the monetary authority would exacerbate the downward rigidity of wages and prices, thus making it more difficult to deal with future supply shocks. Such arguments are cases of the Lucas [12] econometric policy critique, since they suggest that policy changes will cause parameter shifts. Neither of these arguments is implausible on its face. The problem is that it is hard to know how to evaluate them until they are formalized in theoretical models and then tested empirically. This paper takes one small step in that direction by augmenting two popular macro models with rational expectations so that they are capable of dealing with supply shocks, and then examining both the present and future disaster arguments in the context of each.